Why Does Water Get in Your Basement?

This can range from a nuisance to a serious problem for a home, but before you call a company to spend large amounts of money, there are a couple simple things you should check.

The Roof is a Primary Source of that Water

First, where is the water coming from? Much of it comes from your roof, a large watershed system. A 2,500 square foot roof receiving one inch of rainfall will deposit 1,500 gallons of water on the ground around your house. One foot of melting snow on your roof can also deposit 1,500 gallons of water. Valleys in your roof can concentrate it into small areas. If that water is not properly managed, it can end up in your basement.

How to Properly Manage Roof Runoff

Gutters Starting from the top down, look at the gutters. Are they clogged? Are they pitched properly so the water runs to the downspouts? Are they leaking? Ineffective gutters will allow the water to flow over them onto the ground. They can also allow water to travel along the soffit and down into the walls.
A customer in Lake Geneva had an almost completely clogged gutter.

Downspouts Next are the downspouts. Are they connected? How far from the house do the runouts extend? If only 6 inches to 2 feet, that water will end up in your basement. Consider adding extensions to direct the water at least 10 feet away from the house.
The runout for the downspout on this Fontana home is too short, even if it were connected.

Managing Water on the Ground

The ground around the house is a most important factor. Does the ground around the foundation of your home slope away from the house? If not, the water collects there, soaks into the ground and piles up against your foundation wall. The weight of this accumulated water creates “hydrostatic pressure” (i.e. “standing water” pressure). This pressure will force the water through the joint where the basement floor meets the wall, or any cracks or gaps in the wall. It will even force its way through the walls—especially more porous concrete block walls—causing them to “weep”. If this standing water freezes, its expansion can crack, bow or buckle the foundation wall.

Creating a slope away from the house can reduce many basement water problems. The slope should be at least 1 inch per foot extending for 10 feet from the house. Make sure the soil is packed to reduce settling. A cap of clay over the soil can also be added. This diagram shows the proper downspout runout and ground slope to move water away from your home.

Managing Water Underground

Ground Water Even with proper sloping ground, there can still be water outside your foundation due to ground water. This is water that is flowing between layers of soil, or not absorbing immediately due to varying absorption rates of different types of soil (e.g. clay vs. loam). This is where a perimeter drainage system comes in.

Drain Tile Your home should have drain tile around the “footing” of the foundation wall. Today this drain tile is usually in the form of a flexible plastic pipe with small holes, which allows water to seep into it. It collects the water outside the basement walls and channels it through a hole in the foundation wall and into the sump “well” (or sump “basket”). The pump sends the water out onto the ground, hopefully well away from the house.

This diagram shows a cross-section of drain tile on the footing of the foundation wall.

What if the Drain Tile Fails?

Over time this drain tile, if not properly installed, can fail due to clogging or tree roots. Here is a link to an excellent article that goes more in-depth into this subject.

Remedial Treatment If the drain tile system is compromised or failed, then an interior solution may be necessary. These systems will make a narrow channel at the base of the wall to collect any water entering and channel it to the sump well. Basically they act as drain tile on the inside of the wall, collecting water after it has come into the basement.

Before you Spend a Lot of Money…

Before calling a waterproofing company, check your water management systems and the slope around your house. This will help to address the source of the water rather than after it is in your basement.

If you need your gutters cleaned, we offer that service. Please call us here at TLC Property Services at
(262) 245-8828.

Next Post: What About Sump Pump Backup Systems? TLC Property Services is a division of TLC Cleaning Service, Inc.